The application proposes to study the determinants of birthweight (BW) and infant mortality (IM), and of the changes in them that have occurred during the past 24 years among North Carolina's blacks, Native Americans and whites. Determinants and changes in BW distributions, BW-specific mortality, the timing and level of IM over the first year of life, and the importance of various causes of infant deaths (as well as changes in the timing and levels of cause-specific IM) will be investigated. The long term objectives are to obtain an integrated and comprehensive understanding of the determinants of IM and its decline. Specific aims include: (1) Describe differences by race, individual and community-level risk factors in changes that have occurred in BW distributions, and in the timing and levels of total and cause- specific IM at and by each successive infant age. (2) Model the impact of race, individual and community-level risk factors on BW distributions and the level of total and cause-specific IM. (3) Decompose change in BW and total and cause-specific IM to change in composition with respect to important individual and community-level risk factors versus change in the risk of low BW and IM in subgroups formed by these factors. (4) Perform county- level analysis to identify conditions not included in the individual- level analyses that explain unusually good or poor improvement in counties in BW and IM. Methods to be used include cause-elimination life tables to control for competing risks in causes of death; multivariable modeling techniques including linear regression, polytomous logit and hazard models; decomposition techniques that include interaction effects and causal structuring and extending those techniques to include more factors; and model-based standardization.